Looking at my sources that are in the UIM Operator Console, I am not seeing that there are any ecometer items being polled. I have configured the sources in OC, and see that they are polling.
Release : 20.4
Component : UIM - ECOMETER_ADMIN
Metrics are not turned on in Admin Console.
Once completed with the OC configuration of ecometer, you will need to open the probe in Admin Console and configure the metrics to be polled: